- Posts: 1382
- Joined: Tue Jun 02, 2015 7:47 am
- Location: Netherlands
This can happen a number of ways, notably when the default resolution differs from the point in the flow where the mask is used. A way to stop it is to define the resolution of the mask node explicitly, using the "Custom" option under the "Image" tab in the mask node itself - I tend to do this as a habit just to be safe. Then when the comp is written and read back the mask keeps the defined resolution.
If you have a number of mask nodes feeding into each other you only have to do this for the first node (the one furthest from the merge or whatever) and the rest pick it up.